The invention relates to digital tape drive storage devices, and in particular, to an adjustment system for quickly and accurately adjusting the vertical position of the various adjustable components in a tape path.
Digital data is stored on tape drives utilizing a variety of designs, but in all cases, magnetic tape media is wound between a pair of tape reels as data is transferred to or from the tape media. In the art of data storage, the physical space required to store data is an important concern. To conserve space, tape drives often use a single reel tape cartridge design. The single reel tape cartridge design utilizes a supply reel located within the tape cartridge and a takeup reel located within the tape drive. After the tape cartridge is inserted into the tape drive, the tape media is connected to the takeup reel and wound through an internal tape path between the takeup reel and the supply reel as data is written and read from the tape media.
One example of the internal tape path includes a guide roller tape path located between the supply reel and the take up reel. The guide roller tape path comprises a plurality of guide rollers configured to guide the tape media as it is wound between the supply reel and the take up reel. A tape head located in the tape path reads and writes the digital data to and from the tape media as the tape media passes over the tape head. The digital data is written to and read from the tape media in rows, or tracks, running in a longitudinal direction relative to the tape media. To read or write data on a specific track, the tape head must align with the track as the tape media passes over the tape head.
Improvements in the art of magnetic tape media have allowed data to be written to and read from the tape media on continually narrower and more closely spaced tracks. To prevent errors in reading and writing data, the tape path traveled must be reproducible with a high degree of accuracy to accommodate these narrower tracks and maintain alignment of the tape head and tape track.
To achieve these tolerances in reproducibility the tape path must be precisely adjusted to prevent the tape media from moving unpredictably as it passes over the tape head. Thus, one of the final steps in tape drive production is adjustment of the vertical position of the various components in the tape path. In the case of a guide roller tape path, an operator uses a fixture to secure the tape drive with reference to a plane representing the adjustment height of the guide rollers and a plane representing the adjustment height of the takeup reel and a supply reel interface. The supply reel interface is configured to represent the vertical position of the supply reel contained in the tape cartridge when the tape cartridge is loaded into the tape drive. The fixture rests on a granite surface with the reference planes orientated parallel to the granite surface. The operator uses a tool referred to in the art as a height gauge, to individually adjust each guide roller, the takeup reel, and the supply reel interface to the appropriate height for tape drive operation.
Unfortunately, the adjustment process is time consuming and prone to both operator and equipment errors at different stages of adjustment. For example, a first source of error occurs when the height gauge is damaged resulting in an inaccurate measurement of the component heights. A second source of error occurs where the height gauge is misinterpreted or misread by the operator. The operator can also introduce a third source of error during re-calibration of the reference plane. Often the individual guide rollers are adjusted to different heights to accommodate various operations of the tape drive. In this case the reference plane must be re-calibrated before adjustment of the next guide roller. When these errors occur they are often not detected until final testing of the drive. Thus, all other drives adjusted during the interim period are questionable, and must be checked and possibly re-adjusted. Furthermore, since no record is kept of the adjustment process, auditing and re-adjustment is difficult to control.
Therefore a need exists in the art of tape drives for an improved tape path adjustment system that yields a more accurately adjusted tape drive with a higher degree of certainty.
The present invention overcomes the problems outlined above and advances the art by providing an automated adjustment system that allows an operator to quickly and accurately adjust the position of the various adjustable components in a tape path. The present adjustment system comprises an automated adjustment tool connected to a processing system. The automated adjustment tool comprises a plurality of probes connected to a nest fixture. The nest fixture is configured to receive a tape drive and securely position the tape drive for adjustment of the tape path. The plurality of probes are configured to individually engage the adjustable components in the tape path and provide a computer readable output to the processing system that indicates the vertical position of the individual components. The processing system is configured to receive the computer readable outputs, convert the computer readable outputs into measurements, and display the measurements on a display for an operator. The operator then uses the displayed measurements to adjust the individual components to a reference position that corresponds to the appropriate vertical position of each component.
In some examples of the present adjustment system, the processing system is configured to store the measurements for a plurality of tape drives adjusted using the adjustment system to provide an audit record of the tape drive adjustment process. In other examples of the adjustment system, a limit switch connected to the nest fixture is used to indicate tape drive loading status. Thus, if the tape drive is properly loaded, operation of the automated adjustment tool is permitted. If the tape drive is not properly loaded, operation of the automated adjustment tool is prevented. In still yet other examples of the adjustment system, the nest fixture also includes an adjustable stop that positions the tape drive in the horizontal direction so that the individual probes are aligned with a corresponding individual component in the tape path.
A first advantage of the present adjustment system is that it provides simultaneous measurements that indicate the present vertical positions of the various adjustable components in the tape path. A second advantage of the present adjustment system is that throughput of the adjustment process is significantly increased by the simultaneous measurement of the individual vertical positions. A third advantage of the present adjustment system is that it automates the current measurement and calibration of the reference plane for the various adjustable components of the tape path. A fourth advantage of the present adjustment system is that any probe position can be considered as the reference position so that if the desired height of an adjustable component changes, only the processor inputs need to be changed. The operator may still use the same reference position for adjustment, thereby reducing operator error. A fifth advantage of the present adjustment system is that it can accommodate a variety of tape drive designs for adjustment of a variety of tape paths. One skilled in the art can appreciate that this represents a significant advantage during tape drive design changes. A sixth advantage of the present adjustment system is the storage of the tape drive measurements to provide the audit record of the tape drive adjustment process.